### Non-recursive Volume Ownership (FSGroup) graduates to Beta

By default, the `fsgroup` setting, if specified, recursively updates permissions for every file in a volume on every mount. This can make mount, and pod startup, very slow if the volume has many files. 

* Fix stackdriver metrics for node memory using wrong metric type ([#63535](https://github.co/kubernetes/kubernetes/pull/63535), [@serathius](https://github.com/serathius))
* fix mount unmount failure for a Windows pod ([#63272](https://github.com/kubernetes/kubernetes/pull/63272), [@andyzhangx](https://github.com/andyzhangx))

#### General Fixes and Reliability

- Fix: azure file mount timeout issue ([#88610](https://github.com/kubernetes/kubernetes/pull/88610), [@andyzhangx](https://github.com/andyzhangx)) [SIG Cloud Provider and Storage]
- Fix: corrupted mount point in csi driver ([#88569](https://github.com/kubernetes/kubernetes/pull/88569), [@andyzhangx](https://github.com/andyzhangx)) [SIG Storage]

- Fix: azure file mount timeout issue ([#88610](https://github.com/kubernetes/kubernetes/pull/88610), [@andyzhangx](https://github.com/andyzhangx)) [SIG Cloud Provider and Storage]
- Fix: corrupted mount point in csi driver ([#88569](https://github.com/kubernetes/kubernetes/pull/88569), [@andyzhangx](https://github.com/andyzhangx)) [SIG Storage]

* fix race condition issue for smb mount on windows ([#75371](https://github.com/kubernetes/kubernetes/pull/75371), [@andyzhangx](https://github.com/andyzhangx))
* fix smb unmount issue on Windows ([#75087](https://github.com/kubernetes/kubernetes/pull/75087), [@andyzhangx](https://github.com/andyzhangx))

pkg syscall (freebsd-386-cgo), func Umask(int) int
pkg syscall (freebsd-386-cgo), func Undelete(string) error
pkg syscall (freebsd-386-cgo), func UnixRights(...int) []uint8
pkg syscall (freebsd-386-cgo), func Unmount(string, int) error
pkg syscall (freebsd-386-cgo), func Wait4(int, *WaitStatus, int, *Rusage) (int, error)
pkg syscall (freebsd-386-cgo), func Write(int, []uint8) (int, error)

- On compatible systems, a mounter's Unmount implementation is changed to not return an error when the specified target can be detected as not a mount point. On Linux, the behavior of detecting a mount point depends on `umount` command is validated when the mounter is created. Additionally, mount point checks will be skipped in CleanupMountPoint/CleanupMountWithForce if the mounter's Unmount having the changed behavior of not returning error when target is not a...

* Because some plugins mount volume on sub-directory of volume path, we need to distinguish between volume path and mount path to fix issue in reconstruction. ([#74653](https://github.com/kubernetes/kubernetes/pull/74653), [@cofyc](https://github.com/cofyc))

* Fix space issue in volumePath with vSphere Cloud Provider ([#38338](https://github.com/kubernetes/kubernetes/pull/38338), [@BaluDontu](https://github.com/BaluDontu))
* Fix issue when attempting to unmount a wrong vSphere volume ([#37413](https://github.com/kubernetes/kubernetes/pull/37413), [@BaluDontu](https://github.com/BaluDontu))

vSphere. ([#59328](https://github.com/kubernetes/kubernetes/pull/59328), [@divyenpatel](https://github.com/divyenpatel))

* Emit number of bound and unbound persistent volumes as Metrics. This PR adds four kinds of Volume Metrics for kube-controller-manager: bound PVC numbers, unbound PVC numbers, bound PV numbers and unbound PV numbers. The PVC metrics use namespace as dimension and the PV metrics use StorageClassName as its dimension. With these metrics we can better monitor the use...